/Engine/Source/Runtime/Engine/Classes/Camera/CameraModifier.h
Default just returns ViewRotation unchanged
Return true to prevent subsequent (lower priority) modifiers to further adjust rotation, false otherwise.
virtual bool ProcessViewRotation ( class [AActor](API\Runtime\Engine\GameFramework\AActor) * ViewTarget, float DeltaTime, FRotator & OutViewRotation, FRotator & OutDeltaRot )